High resolution single photon emission computed tomography (spect) system

ABSTRACT

A high resolution single photon emission computed tomography (SPECT) imaging system comprising:
         a rotating ring for surrounding anatomy which is to be imaged;   at least one camera mount movably mounted to the rotating ring so that the camera mount can be moved radially relative to the axis of rotation of the rotating ring; and   at least one gamma camera carried on the at least one camera mount, wherein the at least one gamma camera is focused on a single SPECT focal point;   whereby, when the rotating ring is rotated about the anatomy which is to be imaged and the at least one camera mount is moved radially on the rotating ring, the single SPECT focal point of the at least one gamma camera carried by a camera mount follows a spiral pattern through the anatomy, whereby to produce a scan of the anatomy.

REFERENCE TO PENDING PRIOR PATENT APPLICATION

This patent application claims benefit of pending prior U.S. ProvisionalPatent Application Ser. No. 61/351,750, filed Jun. 4, 2010 by Andrew P.Tybinkowski et al. for HIGH RESOLUTION SINGLE PHOTON EMISSION COMPUTEDTOMOGRAPHY (SPECT) SYSTEM (Attorney's Docket No. NEUROLOGICA-26 PROV),which patent application is hereby incorporated herein by reference.

FIELD OF THE INVENTION

This invention relates to anatomical imaging systems in general, andmore particularly to single photon emission computed tomography (SPECT)systems.

BACKGROUND OF THE INVENTION

Various types of anatomical imaging systems are well known in the art.

By way of example but not limitation, X-ray imaging systems comprise anX-ray source and an X-ray detector. The X-ray source is disposed on oneside of the anatomy which is to be imaged, and the X-ray detector isdisposed on the other side of the anatomy which is to be imaged. TheX-ray detector captures the X-rays which pass through the anatomy,thereby forming a 2D image of the anatomy. Such 2D X-ray imaging systemsare now in widespread use in hospitals, surgical centers, dentaloffices, etc.

By acquiring multiple 2D images from multiple angles of view, andsubsequently assembling the data from those multiple 2D images usingcomputed tomography (CT) techniques, 3D images of the anatomy can beproduced. Such CT imaging systems are now in widespread use inhospitals, surgical centers and the like.

Numerous other imaging systems are well known in the art. By way ofexample but not limitation, ultrasound imaging systems and magneticresonance imaging (MRI) systems are two other types of imaging systemswhich are now in widespread use around the world.

Another type of imaging system, and the one to which the presentinvention is directed, relies on scintigraphy, i.e., where radioisotopesare positioned internally within the body, and then a camera is used tocapture and form an image of the radiation emitted by the radioisotopes.These scintigraphy systems may be relatively simple 2D systems or theymay employ computed tomography (CT) techniques so as to produce 3Dimages of the anatomy.

One well known type of scintigraphy system is the single photon emissioncomputed tomography (SPECT) system, where one or more moving camerasdetect gamma radiation emitted by radioisotopes positioned within thebody so as to produce multiple 2D images from multiple angles of view,and then computed tomography (CT) techniques are used to assemble theacquired 2D images into a 3D image.

Another well known type of scintigraphy system is the positron emissiontomography (PET) system. This imaging system uses a radioisotope tracer,which emits positrons which then annihilate adjacent electrons, causinggamma photons to be emitted in opposite directions—these gamma photonsare detected by the system so as to produce multiple 2D images frommultiple angles of view, and then these multiple 2D images areassembled, using computed tomography (CT) techniques, into 3D images.

In general, PET imaging systems have a higher resolution than SPECTimaging systems. However, SPECT imaging systems are generallysignificantly less expensive to build and operate than PET imagingsystems—this is because SPECT imaging systems are generally able to uselonger-lived, and more easily-obtainable, radioisotopes than PET imagingsystems, among other things.

Accordingly, there is currently a need for a new and improved SPECTimaging system which provides increased resolution compared to currentSPECT imaging systems.

In addition to the foregoing, in prior art SPECT imaging systems,multiple gamma cameras have generally been used to acquire the multiple2D images from multiple angles of view. However, in prior art SPECTsystems, complex electromechanical systems have generally been requiredin order to control the movement of the multiple gamma cameras. The useof multiple gamma cameras, and their complex electromechanical controlsystems, significantly increases the cost to build and maintain suchSPECT imaging systems.

Accordingly, there is a need for a new and improved SPECT imaging systemwhich utilizes a simplified construction.

SUMMARY OF THE INVENTION

These and other objects of the present invention are addressed by anovel high resolution single photon emission computed tomography (SPECT)system which provides high resolution scanning while employing asimplified construction. The novel SPECT system of the present inventiongenerally comprises a rotating ring which surrounds the anatomy which isto be imaged. At least one camera mount is movably mounted to therotating ring so that the camera mount can be moved radially relative tothe rotating ring (i.e., so that the camera mount can be moved inwardlyor outwardly relative to the axis of rotation of the rotating ring). Thecamera mount carries a plurality of gamma cameras thereon, with theplurality of gamma cameras on that camera mount all being focused on asingle SPECT focal point. As a result of the foregoing construction, asthe rotating ring is rotated about the patient and the camera mount ismoved radially on the rotating ring, the single SPECT focal point of themultiple gamma cameras carried by that camera mount follows a spiralpattern through the anatomy. As a result, the anatomy traversed by thesingle SPECT focal point is scanned by the SPECT imaging system so as toproduce a scan of the anatomy. While such scanning is occurring, theanatomy and/or the rotating ring are preferably moved longitudinallyrelative to one another, in the manner of a CT or MRI machine, so as toproduce volume scanning of the anatomy. In this way, a 3D image of thepatient's anatomy can be produced.

In one preferred form of the invention, two camera mounts are providedon the rotating ring, with the two camera mounts being disposeddiametrically opposed to one another on the rotating ring. With thisconstruction, each of the two SPECT focal points follows a spiralpattern through the anatomy, with the two SPECT focal points beingdiametrically opposed to one another as they follow their respectivespiral paths. Preferably the imaging system is constructed so that thetwo SPECT focal points can be superimposed on one another when theirrespective camera mounts are appropriately positioned on the rotatingring.

In another preferred form of the invention, just one camera mount isprovided on the rotating ring, so that just one SPECT focal pointtraverses the anatomy.

And in another preferred form of the invention, three or more cameramounts are provided, so that three or more SPECT focal points traversethe anatomy.

In another preferred form of the invention, there is provided a highresolution single photon emission computed tomography (SPECT) imagingsystem comprising:

a rotating ring for surrounding anatomy which is to be imaged;

at least one camera mount movably mounted to the rotating ring so thatthe camera mount can be moved radially relative to the axis of rotationof the rotating ring; and

at least one gamma camera carried on the at least one camera mount,wherein the at least one gamma camera is focused on a single SPECT focalpoint;

whereby, when the rotating ring is rotated about the anatomy which is tobe imaged and the at least one camera mount is moved radially on therotating ring, the single SPECT focal point of the at least one gammacamera carried by a camera mount follows a spiral pattern through theanatomy, whereby to produce a scan of the anatomy.

In another preferred form of the invention, there is provided a methodfor imaging anatomy, the method comprising:

providing a high resolution single photon emission computed tomography(SPECT) imaging system comprising:

-   -   a rotating ring for surrounding anatomy which is to be imaged;    -   at least one camera mount movably mounted to the rotating ring        so that the camera mount can be moved radially relative to the        axis of rotation of the rotating ring; and    -   at least one gamma camera carried on the at least one camera        mount, wherein the at least one gamma camera is focused on a        single SPECT focal point; and

rotating the rotating ring about the anatomy which is to be imaged andmoving the at least one camera mount radially on the rotating ring, sothat the single SPECT focal point of the at least one gamma cameracarried by a camera mount follows a spiral pattern through the anatomy,whereby to produce a scan of the anatomy.

In another preferred form of the invention, there is provided a methodfor imaging anatomy, the method comprising:

providing at least one camera focused on a focal point; and

simultaneously moving, circumferentially and radially, the at least onecamera relative to the anatomy so that the focal point follows a spiralpattern through the anatomy, whereby to produce a scan of the anatomy.

BRIEF DESCRIPTION OF THE DRAWINGS

These and other objects and features of the present invention will bemore fully disclosed or rendered obvious by the following detaileddescription of the preferred embodiments of the invention, which is tobe considered together with the accompanying drawings wherein likenumbers refer to like parts, and further wherein:

FIGS. 1-4 are schematic views of a SPECT imaging system formed inaccordance with the present invention, wherein the SPECT imaging systemcomprises a rotating ring and two camera mounts diametrically opposed onthe rotating ring so that two SPECT focal points traverse the anatomy;

FIG. 5 is a schematic view showing the two spiral paths that arefollowed by the two SPECT focal points provided by the SPECT imagingsystem of FIGS. 1-4;

FIGS. 6-17 are schematic views showing selected aspects of a SPECTimaging system formed in accordance with the present invention, whereinthe SPECT imaging system is adapted to move relative to the anatomy ofthe patient during scanning so as to produce volume scanning of theanatomy, e.g., in a manner analogous to that of the CT scanner disclosedin U.S. Pat. No. 7,175,347, which patent is hereby incorporated hereinby reference; and

FIGS. 18-42 are schematic views showing selected aspects of a SPECTimaging system formed in accordance with the present invention, whereinthe SPECT imaging system is adapted to move relative to the anatomy soas to produce volume scanning of the anatomy, e.g., in a manneranalogous to that of the CT scanner disclosed in U.S. Pat. No.7,175,347.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

The present invention comprises a novel high resolution single photonemission computed tomography (SPECT) system which provides highresolution scanning of anatomy while employing a simplifiedconstruction.

More particularly, and looking now at FIGS. 1-4, there is shown a novelSPECT system 5 formed in accordance with the present invention. NovelSPECT system 5 generally comprises a rotating ring 10 which surroundsthe anatomy which is to be scanned. Rotating ring 10 includes a bore 12for receiving the anatomy which is to be scanned. At least one cameramount 15 (e.g., 15A, 15B, etc.) is movably mounted to rotating ring 10so that the camera mount can be moved radially relative to the rotatingring (i.e., so that the camera mount can be moved inwardly or outwardlyrelative to the axis of rotation of the rotating ring). By way ofexample but not limitation, the at least one camera mount 15 may bemounted to rails 20, which are in turn mounted to rotating ring 10, suchthat the at least one camera mount may move radially relative torotating ring 10. The at least one camera mount carries a plurality ofgamma cameras 25 (FIG. 4) thereon, with the plurality of gamma cameras25 on that camera mount all being focused on a single SPECT focal point30. More particularly, each of the gamma cameras comprises a collimator35, and a scintillation crystal and associated electronics 40. Thecollimator is adapted to filter (or “focus”) the field of radiation 45emanating from the body of the patient, i.e., the radiation emanatingfrom the SPECT focal point 30 to which that gamma camera is directed.The radiation passed by collimator 35 is then detected by scintillationcrystal and associated electronics 40. As a result of the foregoingconstruction, as rotating ring 10 is rotated about the patient andcamera mount 15 is moved radially on the rotating ring, the single SPECTfocal point 30 of the gamma cameras 25 carried by that camera mount 15follows a spiral path 50 through the anatomy. See FIG. 5. As a result,the anatomy traversed by the single SPECT focal point 50 is scanned bythe SPECT imaging system so as to produce a scan of the anatomy.

While such scanning is occurring, the anatomy and/or the rotating ring10 is/are preferably moved longitudinally relative to one another (i.e.,along the axis of rotation of rotating ring 10), in the manner of a CTor MRI machine, so as to produce volume scanning of the anatomy. In thisway, a 3D image of the patient's anatomy can be produced. By way ofexample but not limitation, the new SPECT imaging system may be adaptedto move relative to the anatomy of the patient during scanning so as toproduce volume scanning of the anatomy, e.g., in the manner of themoving CT scanner disclosed in U.S. Pat. No. 7,175,347, which patent ishereby incorporated herein by reference. Alternatively, the new SPECTimaging system may include a moving bed (not shown) which is adapted tomove the anatomy of the patient relative to rotating ring 10 of thescanner during scanning so as to produce volume scanning of the anatomy.

In one preferred form of the invention, and as shown in FIGS. 1-4, twocamera mounts 15A, 15B are provided on rotating ring 10, with the twocamera mounts being disposed diametrically opposed to one another on therotating ring. As noted above, each camera mount 15A, 15B carries aplurality of gamma cameras 25 thereon, with gamma cameras 25 beingfocused on SPECT focal points 30A, 30B, respectively. On account of thisconstruction, two SPECT focal points 30A, 30B are provided, with each ofthe two SPECT focal points 30A, 30B following their own spiral patterns50A, 50B through the anatomy, with the two SPECT focal points 30A, 30Bbeing diametrically opposed to one another as they follow theirrespective spirals 50A, 50B through the anatomy. See FIG. 5. PreferablySPECT imaging system 5 is constructed so that the two SPECT focal points30A, 30B can be superimposed on one another when their respective cameramounts 15A, 15B are appropriately positioned on rotating ring 10.

In another preferred form of the invention, just one camera mount 15 isprovided on rotating ring 10, so that just one SPECT focal point 30 isprovided.

And in another preferred form of the invention, three or more cameramounts 15 are provided, so that three or more SPECT focal points 30 areprovided.

Looking next at FIGS. 6-17, there are shown selected aspects of a SPECTimaging system 5 formed in accordance with the present invention,wherein the SPECT imaging system 5 is adapted to move relative to theanatomy of the patient during scanning so as to produce volume scanningof the anatomy, e.g., in a manner analogous to that of the CT scannerdisclosed in U.S. Pat. No. 7,175,347, which patent is herebyincorporated herein by reference. More particularly, in FIGS. 6-17,there is shown a frame 55 (FIG. 9) to which rotating ring 10 is mounted,and rails 20 which are mounted to rotating ring 10 and to which a pairof diametrically-opposed camera mounts 15A, 15B are mounted. Also shownis an exemplary gamma camera 25 (FIGS. 14 and 15) comprising itsconstituent collimator 35 (FIGS. 14-17) and its constituentscintillation crystal and associated electronics 40. Also shown aremeans for moving camera mounts 15A, 15B on rails 20, whereby to movecamera mounts 15A, 15B in a radial manner relative to rotating ring 10.More particularly, in one preferred form of the invention, each of thecamera mounts 15A, 15B has a lever 60 secured thereto. A drive unit 65moves levers 60, whereby to move camera mounts 15 on rails 20 and henceto move camera mounts 15 radially relative to rotating ring 10. Inaddition to the foregoing, the SPECT imaging system 5 shown in FIGS.6-17 also comprises centipede belt drives 70 for moving frame 55relative to a patient who is disposed in bore 12, and hence movingrotating ring 10 (and hence camera mounts 15 and gamma cameras 25)relative to a patient who is disposed in bore 12.

FIGS. 18-42 show additional selected aspects of a SPECT imaging system 5formed in accordance with the present invention. As seen in FIGS. 31-42,drive unit 65 comprises a motor 75 which drives a pair of screws 80. Aball nut 85 is mounted on each of the screws 80, such that rotation ofscrews 80 causes longitudinal motion of ball nuts 85 along screws 80.Note that screws 80 have threads 90 which turn in opposing directions,so that rotation of screws 80 in the same direction causes the pair ofball nuts 85 to move in opposing directions on their respective screws,i.e., either away from one another or towards one another. Levers 60 aremounted to ball nuts 85 and to camera mounts 15A, 15B. As a result ofthis construction, when motor 75 turns in one direction, ball nuts 85are caused to move apart from one another, whereby to move camera mounts15A, 15B apart from one another; and when motor 75 turns in the oppositedirection, ball nuts 85 are caused to move toward one another, wherebyto move camera mounts 15A, 15B toward one another. If desired, a belt 95can be used to transfer rotary motion to a parallel screw/ball nutmechanism located on an opposing side of bore 12.

MODIFICATIONS

It will be understood that many changes in the details, materials, stepsand arrangements of parts, which have been herein described andillustrated in order to explain the nature of the invention, may be madeby those skilled in the art without departing from the principles andscope of the present invention.

1. A high resolution single photon emission computed tomography (SPECT)imaging system comprising: a rotating ring for surrounding anatomy whichis to be imaged; at least one camera mount movably mounted to therotating ring so that the camera mount can be moved radially relative tothe axis of rotation of the rotating ring; and at least one gamma cameracarried on the at least one camera mount, wherein the at least one gammacamera is focused on a single SPECT focal point; whereby, when therotating ring is rotated about the anatomy which is to be imaged and theat least one camera mount is moved radially on the rotating ring, thesingle SPECT focal point of the at least one gamma camera carried by acamera mount follows a spiral pattern through the anatomy, whereby toproduce a scan of the anatomy.
 2. A high resolution single photonemission computed tomography (SPECT) imaging system according to claim 1wherein at least one of the anatomy and the rotating ring is movedlongitudinally relative to the other during scanning, whereby to producea volume scan of the anatomy.
 3. A high resolution single photonemission computed tomography (SPECT) imaging system according to claim 2wherein the rotating ring is moved longitudinally relative to thepatient.
 4. A high resolution single photon emission computed tomography(SPECT) imaging system according to claim 3 wherein the rotating ring ismounted to a frame, and further wherein the frame is moved along asurface using a continuous loop drive.
 5. A high resolution singlephoton emission computed tomography (SPECT) imaging system according toclaim 4 wherein the continuous loop drive comprises a pair of centipedebelt drives.
 6. A high resolution single photon emission computedtomography (SPECT) imaging system according to claim 2 wherein thepatient is moved longitudinally relative to the rotating ring.
 7. A highresolution single photon emission computed tomography (SPECT) imagingsystem according to claim 6 wherein the patient is moved relative to therotating ring using a motorized bed.
 8. A high resolution single photonemission computed tomography (SPECT) imaging system according to claim 1wherein the at least one gamma camera carried on the at least one cameramount comprises a collimator and a scintillation crystal and associatedelectronics.
 9. A high resolution single photon emission computedtomography (SPECT) imaging system according to claim 1 wherein aplurality of gamma cameras are carried on the at least one camera mount,with the plurality of gamma cameras on that camera mount all beingfocused on a single SPECT focal point.
 10. A high resolution singlephoton emission computed tomography (SPECT) imaging system according toclaim 1 wherein a plurality of camera mounts are movably mounted on therotating ring so that each camera mount can be moved radially relativeto the axis of rotation of the rotating ring, and further wherein eachof the plurality of camera mounts comprises at least one gamma camerafocused on a single SPECT focal point for that camera mount.
 11. A highresolution single photon emission computed tomography (SPECT) imagingsystem according to claim 10 wherein a plurality of gamma cameras arecarried on each of the camera mounts, with the plurality of gammacameras on a given camera mount all being focused on a single SPECTfocal point for that camera mount. 12-13. (canceled)
 14. A highresolution single photon emission computed tomography (SPECT) imagingsystem according to claim 10 wherein at least three camera mounts areprovided on the rotating ring.
 15. A high resolution single photonemission computed tomography (SPECT) imaging system according to claim 1wherein the at least one camera mount is moved relative to the rotatingring using a rotating screw and a ball nut fixed to the at least onecamera mount and riding on the rotating screw.
 16. A method for imaginganatomy, the method comprising: providing a high resolution singlephoton emission computed tomography (SPECT) imaging system comprising: arotating ring for surrounding anatomy which is to be imaged; at leastone camera mount movably mounted to the rotating ring so that the cameramount can be moved radially relative to the axis of rotation of therotating ring; and at least one gamma camera carried on the at least onecamera mount, wherein the at least one gamma camera is focused on asingle SPECT focal point; and rotating the rotating ring about theanatomy which is to be imaged and moving the at least one camera mountradially on the rotating ring, so that the single SPECT focal point ofthe at least one gamma camera carried by a camera mount follows a spiralpattern through the anatomy, whereby to produce a scan of the anatomy.17. A method according to claim 16 wherein at least one of the anatomyand the rotating ring is moved longitudinally relative to the otherduring scanning, whereby to produce a volume scan of the anatomy.
 18. Amethod according to claim 17 wherein the rotating ring is movedlongitudinally relative to the patient.
 19. A method according to claim18 wherein the rotating ring is mounted to a frame, and further whereinthe frame is moved along a surface using a continuous loop drive.
 20. Amethod according to claim 19 wherein the continuous loop drive comprisesa pair of centipede belt drives.
 21. A method according to claim 17wherein the patient is moved longitudinally relative to the rotatingring.
 22. A method according to claim 21 wherein the patient is movedrelative to the rotating ring using a motorized bed.
 23. A methodaccording to claim 16 wherein the at least one gamma camera carried onthe at least one camera mount comprises a collimator and a scintillationcrystal and associated electronics.
 24. A method according to claim 16wherein a plurality of gamma cameras are carried on the at least onecamera mount, with the plurality of gamma cameras on that camera mountall being focused on a single SPECT focal point.
 25. A method accordingto claim 16 wherein a plurality of camera mounts are movably mounted onthe rotating ring so that each camera mount can be moved radiallyrelative to the axis of rotation of the rotating ring, and furtherwherein each of the plurality of camera mounts comprises at least onegamma camera focused on a single SPECT focal point for that cameramount.
 26. A method according to claim 25 wherein a plurality of gammacameras are carried on each of the camera mounts, with the plurality ofgamma cameras on a given camera mount all being focused on a singleSPECT focal point for that camera mount. 27-28. (canceled)
 29. A methodfor imaging anatomy, the method comprising: providing at least onecamera focused on a focal point; and simultaneously moving,circumferentially and radially, the at least one camera relative to theanatomy so that the focal point follows a spiral pattern through theanatomy, whereby to produce a scan of the anatomy.